System and method for authorized digital content distribution

ABSTRACT

A digital content distribution system uses a Digital Rights Management Controller that performs a set of arbitrary tests against the transfer request from one user to another such as user A to user B. Assuming these tests are successful, the DRM sends an encryption key to transferring user A. This encryption key E is taken from a table of encryption key/hash pairs which have been provided to the DRM Controller by an external authority such as the content rights holder. User A encrypts the content using they key provided by the DRM controller and then optionally calculates a hash over the encrypted form of the content E(X) and returns this value to the DRM Controller. On checking the returned hash against the hash from the table the DRM controller knows that user A does indeed have the digital content X in good condition. The DRM Controller then instructs both users A and B that the transfer may proceed. The encrypted form of the content E(X) is transferred from A to B. Once the content transfer has completed B ensures that the received content has been physically written to non-volatile storage (to account for crashes etc. during the next step). B then calculates a hash over the received content and returns this value to the DRM Controller. If this value matches the value previously given then the transfer has been successful and the DRM Controller updates whatever central records are appropriate, while also returning a decrypt key to B to allow it to decrypt the content.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority of U.S. Provisional Patent Application No. 60/647,044 filed on Jan. 26, 2005, entitled “System and Method for Digital Content Distribution.” This application is related to U.S. patent application Ser. No. 11/341,227 entitled “Payment System For The Distribution of Digital Content Using An Intelligent Services Control Point” filed concurrently herewith.

FIELD OF THE INVENTION

The present invention relates generally to the field of digital content distribution in a telecommunications network and, more specifically, to payment mechanisms for the authorized legal distribution of digital content within a peer-to-peer (P2P) environment.

BACKGROUND

Peer-to-peer P2P networks are networks that enable a computer user in possession of digital content to share the digital content with other users without having to transfer to or download the content from a central server. P2P networks have generally been very successful but have existed outside of most legal frameworks. This has lead to considerable controversy including the shutdown of many peer-to-peer networks due to court injunctions and other legal problems. This problem appears to have been solved in conjunction with the Digital Rights Management (DRM) issue but separating DRM and Digital Content Distribution (DCD) has lead to innovative differentiation. Even then this has not really been solved in a generic P2P infrastructure, but has resulted in much more centralized environments.

Current P2P solutions have been created outside of a legal framework and are subject to repeated attack from copyright holders. Their growth is limited by ongoing legality concerns in the minds of potential users which are fostered by the RIAA and like organizations.

Current DRM solutions tend to have originated with rights holders and thus tend to enforce additional restrictions on the use of purchased materials above and beyond those which consumers have come to expect with videocassette recorders (VCRs) and the Compact Cassette. This has lead to consumer resentment. DRM solutions also tend to be somewhat centralized in nature leading to limited, or very expensive systems.

P2P operators have not, historially, been too concerned with content tracking and tracability, nor with the implementation of a legal overlay on a P2P infrastructure. Traditional DRM providers view their value as being in the DRM solution, not in the content distribution component, for which they would typically expect to use commercially available solutions.

Thus, there is a need for a peer-to-peer (P2P) distribution scheme that can incorporate the concepts from digital rights management thereby enabling the distribution of digital content such as music, movies and books while providing just compensation to the owners of such copyrighted works.

It would be desirable to have a P2P digital content distribution system and method that enable charging back to a prepaid account such as a prepaid mobile phone account.

Additionally, it would be desirable to have a P2P digital content distribution system that provides for certification of quality of content thereby ensuring that the downloaded digital files are not corrupted or contain viruses or other problems that would prohibit their legitimate use.

Furthermore, it would be desirable to have a P2P digital content distribution system that provides credits to a customer for the onward distribution of digital content to additional users/customers.

SUMMARY

The present invention enables the legitimate P2P distribution of digital content within a legal framework in which operators do not need to have first hand knowledge or possession of the content thereby enabling operators to claim the equivalent of ‘common carrier’ status in a content environment. Two sharing users, A and B, previously registered with a DRM controller, find by some arbitrary method that they wish to exchange a piece of digital content, X. B requests a copy of digital content X from A, which A is willing to provide and so A sends an acknowledgement back to B. Both A and B register their interest in the content element X with the DRM Controller. Note that in the general case there may be more than one sender (i.e. equivalent to A) for a given request.

The DRM Controller performs a set of arbitrary tests against the transfer request (e.g. does B have sufficient funds, does A officially and legally have possession of X, is it within a window of time in which A is allowed to distribute content etc. etc.) and, assuming these tests are successful, it sends an encryption key E to A. This encryption key E is taken from a table of encryption key/hash pairs which have been provided to the DRM Controller by an external authority such as the copyright owner of digital content X or the party that controls digital distribution of digital content X.

User A encrypts the content using the key provided by the DRM controller and then calculates a hash over the encrypted form of the content E(X) returning this value to the DRM Controller. Because the encryption key, E, is not known ahead of time, user A cannot know the value of the hash a priori and can only calculate it by performing the Encryption/Hash Calculation steps. On checking the returned hash against the hash from the table, the DRM controller knows that User A does indeed have the content element X and it is in good condition (i.e, it has not been altered from the form used to create the key/has pair). The DRM Controller then instructs both A and B that the transfer may proceed.

The encrypted form of the content E(X) is transferred from user A to user B by arbitrary means that are well known in the art. Once the content transfer has completed, B ensures that the received content has been physically written to non-volatile storage (to account for crashes etc. during the next step). B then calculates a hash over the received content and returns this value to the DRM Controller. If this value matches the value previously given then the transfer has been successful and the DRM Controller updates whatever central records are appropriate, while also returning a decrypt key to B to allow it to decrypt the content. A record of the transfer is kept for a period of time such that if B crashed in the period from obtaining the complete content to receiving the decrypt key and decrypting the content then B could request said key again without incurring additional charges.

It will be noted that the DRM Controller never needed to ‘see’ the content. It only requires a set of encrypt key/hash pairs. If these pairs are generated by an external responsible authority then the organization running the DRM Controller need never see or have knowledge of what the content element is. Note that in an extension to the invention if the key/hash pairs are consumed this would serve as a form of audit and tracking for the content rights holder and would also prevent possible attacks based in the re-use of key/hash pairs

In this manner the DRM Controller can certify transfers without ever needing to have access to the content concerned. The content owner can provide keys and signatures. Because back end systems decide if a transfer should, or should not progress, neither sender or receiver can individually circumvent the system

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the architecture of one embodiment of a digital content distribution system in accordance with the present invention;

FIG. 2 depicts the architecture of another embodiment of a digital content distribution system in accordance with the present invention;

FIG. 3 depicts the graphical user interface for use of users of the file sharing process of a digital content distribution system in accordance with the present invention;

FIG. 4 depicts the process flow of the file sharing process in a digital content distribution system in accordance with the present invention;

FIG. 5 depicts an example of the content shared in a digital content distribution system in accordance with the present invention; and,

FIGS. 6A-E depict the graphical user interface screens forming the interface to the DRM self-service web-site in a digital content distribution system in accordance with the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

In FIG. 1 the architecture of a digital content distribution system in accordance with the present invention is shown. User A communicates with a DRM Self-Service Web-Site 100 using a device 130 a for the purpose of inputting various information regarding the distribution of content owned or controlled by User A. Device 130 a may be any type of general purpose personal computer (PC), personal digital assistant (PDA), mobile handset, cellular telephone or other handheld device capable of communicating in a wired or wireless manner with the Internet so as to display one or more user input screen such as those discusses below in relation to FIG. 6. Device 130 a would need software such as an Internet browser, Wireless Access Protocol (WAP) browser or other similar software in order to send and receive data from the DRM Self-Service Web-Site 100. This type of software is well-known in the art.

User A communicates using device 130 a with DRM Self-Service Web-Site 100 in order to specify various parameters with respect to the transfer of content between one or more other users such as User B and User C. FIG. 1 shows the arrangement of components within a typical operational digital content distribution system. In this example, transfer of digital content owned or controlled by User A is transferred between User B and User C using the associated DRM Controller 120. The other components are important for the construction of a physical system but are not as important to the present invention as DRM Controller 120.

DRM Controller 120 communicated with DRM Self-Service Web-Site 100 in order to receive information regarding how to handle a transfer of digital content from one user to another, such as the transfer of digital content from User B to User C. User B and User C communicate with DRM Controller 120 and with each other by using devices 130 b and 130 c which devices are similarly enabled to device 130 a described above, although devices 130 b and 130 c should contain an interface for use by an actual person. A typical transaction would begin with some type of dialog between User B and User C that leads the two to decide that one has content that it would like to share with the other.

Accounting and Content Web (ACW) Server 140 comprises software implemented on a general purpose computer that is capable of keeping track of transfer of digital content and payment of digital content. ACW Server 140 is in communication with DRM Self-Service Web-Site 100 in order to receive information about the amount of compensation a user such as User A desires to receive for transfers of digital content between other user such as User B and User C. ACW Server 140 is also in communication with SCP Pre-Pay Web Service Server 160 that is an intelligent service control point capable of decrementing an account of the user paying for a transfer of content and incrementing one or more of the accounts of the user transferring content and/or the owner of the content being transferred. In this way, P2P transfers of digital content can be accomplished with the knowledge and approval of the owner of the content who is properly compensated for the transfer. SCP Pre-Pay Web Service Server 160 is in communication with the Digital Rights Server (DRS) which is a repository of records associated with the transfer of digital content and payment for such transfers. SCP Pre-Pay Web Service Sever 160 can be any of several known intelligent service control points such as the Telcordia Converged Application Server and/or Real-Time Charging System.

FIG. 2 depicts a more detailed embodiment of a digital content distribution system, in accordance with the present invention. Again User A communicates using a device (not shown) through the Internet 220 with one or more DRM Self Service servers/servlets 230 in order to input various information about the distribution of digital content owned or controlled by User A. ACW Server 140 is broken into two components: Content Registry Web Server 140 a and Content Account Web Server (Digital Rights Management Platform) (“DRMP”) 140 b. Content Registry Web Server 140 a manages the information that plays a role in allowing content to be forwarded between users. That is, it contains user or content-owner “preferences” pertaining to allowing content exchange such as exchange rights spelled out in traditional DRM systems. Content Accounting Web Service 140 b keeps track of the amount a user desires for transfer of specific digital content and communicated through the Internet 220 using a Simple Object Access Protocol (SOAP) 260 with ISCP pre-pay web-services 160 to enable the account of the users and owners of content to properly decremented and incremented in accordance with the payment scheme. Content Accounting Web-Service 140 b can also communicate using Java Data Base Connectivity (JDBC) with DRS 180 in order to directly access records of users of the digital content distribution system.

As with FIG. 1, User B and User C get permission for a transfer of digital content by communicating with DRM Controller 120. DRM Controller 120 communicated with Content Accounting Web Service 140 b and Content Registry Web Server 140 a. In the case of the former, DRM Controller 120 sends information about the transfer so as to enable proper incrementing and decrementing of user accounts. For example, a transfer of digital content from User B to User C could result in a decrementing of the account of User C as well as an incrementing of the accounts of User A and User B. User A, as the owner of the digital content, is likely to receive the majority of the payment made by User C but User B might also receive a small payment as a reward for being the one distributing content on behalf of User/Owner A.

FIG. 3 depicts a few of the graphical user interface (GUI) screens shown by the DRM Controller 120 to users of the system. Interface Screen 310 is the P2P transfer control screen. Interface screen 320 is the interface seen by the receiving peer or user such as User C in the example transaction in FIGS. 1 and 2. Interface Screen 330 is the interface seen by the sending peer/user such as User B.

The flow of content transfer process between User B and User C is shown in FIG. 4. User B and User C have previously registered with DRM controller 120 and have by some arbitary method decided that they wish to exchange a piece of digital content, X at step 400 of FIG. 4. User C requests a copy of digital content X from User B at step 405/410. User B is willing to accept the request and so sends an acknowledgement back to User C at step 415. Both User B and User C register their interest in the digital content X with the DRM Controller 120 at steps 420 and 425 respectively. Note that in the general case there may be more than one sender (i.e. equivalent to A) for a given reception. Digital content X may be any type of digital information including but not limited to digial music, movies, books, magazines, computer software, audiobooks, etc.

At step 430 the DRM Controller 120 performs a set of arbitrary tests against the transfer request. For example the DRM Controller 120 may be designed to query whether User C has sufficient funds. Alternatively, DRM Controller may query whether User B legitimately has a copy of digital content X, or whether it is a time period in which User A is allowed to distribute content. Any number of arbitrary tests can be generated. Assuming these tests are successful, DRM Controller 120 sends an acknowledge (ACK) message back to User C at step 435 and/or an acknowledge (ACK) message with an encryption key E to User B at step 440. This encryption key E is taken from a table of encryption key/hash pairs which have been provided to the DRM Controller by an external authority. For example, the encryption key/hash pairs may be provided by User A, the owner or licensed distributor of digital content X.

User B encrypts the content using they key provided by the DRM Controller 120. User B also peforms a hash function (preferably MD5) over the encrypted digital content and returns this hash to the DRM Contoller 120 at an optional step not shown in FIG. 4. If the hash matches that in the database of the DRM Controller then the DRM Controller instructs User A and User B that the transfer may proceed at an additional optional step not depicted in FIG. 4. User B then transfers the encrypted content to User C by aribtrary meand that are well known in the art at step 445.

Once the content transfer has completed User C ensures that the received content has been physically written to non-volatile storage (to account for crashes) in a step not shown in FIG. 4. User C then calculates a hash over the encrypted form of the content E(X) and returns this hash value to the DRM Controller 120 at step 450. Because the encryption key E is not known ahead of time, User C cannot know the value of the hash a priori and can only calculate it by performing the Encryption/Hash Calculation steps. On checking the returned hash value against the hash from the table the DRM Controller 120 knows that User C does indeed have the digital content X and that the digital content is in good condition. If this value matches the value provided by the content owner User A and stored by the DRM Controller then a transfer of valid content has been successful and the DRM Controller updates whatever central records are appropriate at step 455, while also returning an acknowledge (ACK) message with a decrypt key to User C to allow User C to decrypt the digital content X. A record of the transfer is kept for a period of time such that if User C crashed in the period from obtaining the complete content to receiving the decrypt key and decrypting the content then they could request said key again without incurring additional charges.

It will be noted that the DRM Controller 120 never needed to ‘see’ or possess an actual copy of the digital content. DRM Controller 120 only requires a set of encrypt key/hash pairs. If these pairs are generated by an external responsible authority then the organization running the DRM Controller need never see or have knowledge of what the digital content X is.

In an extension to the invention if the key/hash pairs are consumed this would serve as a form of audit and tracking for the content rights holder and would also prevent possible attacks based in the re-use of key/hash pairs. By “consumed” it is meant that the DRM server would use a key/hash pair for one and only one transaction and would never re-use the transactions for subsequent transactions. Furthermore, the external respository could supply the key//has pairs to the DRM server on demand, when users have comitted to a content transfer.

FIG. 5 depicts an example of digital content that is being transferred from one user to another. Field 510 contains the filenames of the digital content to be transferred. In this example the digital content is MP3 encoded music files. Field 520 contains the encrypt and/or decrypt keys and field 530 contains the related MD5 checksum hash. One line from the file set forth in FIG. 5 is all that is needed for the DRM Controller 120 to be able to validate a specific transfer.

FIGS. 6A-E depict a set of graphical user interface (GUI) screens used by the DRM Self-Service Web Server 100 in order to gather information from the owner of digital content. Screen 610 of FIG. 6A is a user login screen for such a server. Screen 620 of FIG. 6B provides the owner/user with the ability to select the viewing of account balances, billing activity, media, and to “top-up” a pre-pay account balance. Screen 630 of FIG. 6C provides information on the account balance. Screen 640 of FIG. 6D enables the user to view the digital content that he or she has transferred from another source. Screen 650 of FIG. 6E provides an interface for adding money to a pre-pay wallet for the future purchase of digital content.

The above description has been presented only to illustrate and describe the invention. It is not intended to be exhaustive or to limit the invention to any precise form disclosed. Many modifications and variations are possible in light of the above teaching. The applications described were chosen and described in order to best explain the principles of the invention and its practical application to enable others skilled in the art to best utilize the invention on various applications and with various modifications as are suited to the particular use contemplated. 

What is claimed is:
 1. A method comprising: receiving at a controller computing device a request to transfer digital content from a first computing device to a second computing device; receiving at the controller computing device a key/hash pair from a third computing source; sending from the controller computing device an encryption key based on the key/hash pair to the first computing device for encrypting the digital content; the controller computing device authorizing the transfer of the digital content from the first computing device to the second computing device; receiving at the controller computing device from the second computing device a result of a hash function performed on the digital content at the second computing device; the controller computing device comparing the key/hash pair provided by the third computing device to the result of the hash function received at the controller computing device; sending to the second computing device, in response to comparing that the result of the hash function corresponds to the key/hash pair from the controller, a decryption key for decrypting the digital content at the second computing device.
 2. The method of claim 1 wherein the authorizing further comprises: receiving at the controller computing device a result of a hash function performed at the first computing device; comparing at the controller computing device the result of the hash function received from the first computing device with the key/hash pair provided by the third computing device; and authorizing at the controller computing device transfer of the digital content from the first computing device to the second computing device in response to the result of the hash function sent by the first computing device corresponding to the key/hash pair provided by the third computing device.
 3. The method of claim 1 wherein the authorizing further comprises authorizing at the controller computing device transfer of the digital content from the first computing device to the second computing device after performing one or more tests regarding existence of authorized conditions for authorization of transfer of the digital content.
 4. The method of claim 3 wherein the performing one or more tests comprises determining whether the first computing device possesses a legitimate copy of the digital content.
 5. The method of claim 3 wherein the performing one or more tests comprises determining whether the second computing device has an account with sufficient funds to compensate the owner of the digital content.
 6. The method of claim 1 wherein the authorizing further includes authorizing at the controller computing device transfer of the digital content from the first computing device to the second computing device wherein the sending the key/hash pair comprises sending the key/hash pair only for transferring the digital content.
 7. The method of claim 1 further comprising receiving the request to transfer the digital content to the second computing device from the first computing device or the second computing device.
 8. The method of claim 3 wherein the authorizing further comprises sending an acknowledgement from the controller to at least one of the first computing device or the second computing device that the transfer is authorized.
 9. The method of claim 1 further comprising storing at the controller computing device a record of the transfer of the digital content from the first computing device to the second computing device without storing a copy of the digital content at the controller.
 10. The method of claim 9 wherein the storing further comprises storing at the controller computing device a record using an accounting web server.
 11. An apparatus comprising: a controller computing device configured to be in communication with a first computing device and a second computing device to receive a request to transfer digital content from the first computing device to the second computing device; wherein the controller computing device is configured to be in communication with a third computing source to receive a key/hash pair; wherein the controller computing device comprises a tangible computer readable medium storing instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising: authorizing an exchange of digital content between the first computing device and the second computing device; sending to the first computing device an encryption key based on the key/hash pair configured to encrypt the digital content at the first computing device; and sending to the second computing device a decryption key configured to decrypt the digital content at the second computing device.
 12. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising storing encryption keys and hash function results associated with the digital content.
 13. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising receiving requests from the first computing device or the second computing device to authorize the transfer of the digital content from the first computing device to the second computing device.
 14. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising determining whether the transfer is authorized based on one or more tests regarding existence of authorized conditions for authorization of transfer of the digital content.
 15. The apparatus of claim 14 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising determining whether the first computing device possesses a legitimate copy of the digital content.
 16. The apparatus of claim 15 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising storing a hash function performed by the first computing device on the digital content and to store function results associated with the digital content, and using the result of the hash function performed at the first computing device and the function results associated with the digital content to determine whether the first computing device possesses a legitimate copy of the digital content.
 17. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising determining whether funds in an account associated with the second computing device are sufficient to authorize the transfer of the digital content to the second computing device.
 18. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising authorizing incrementing an account associated with the first computing device in response to transfer of the digital content from the first computing device to the second computing device.
 19. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising authorizing decrementing an account associated with the second computing device in response to transfer of the digital content from the first computing device to the second computing device.
 20. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising authorizing incrementing an account associated with the third computing device having an associated ownership with the digital content in response to transfer of the digital content from the first computing device to the second computing device.
 21. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising sending an encryption key to the first computing device to enable the encryption of the digital content prior to transfer to the second computing device.
 22. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising sending a decryption key to the second computing device after the digital content has been transferred from the first computing device to the second computing device.
 23. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising receiving a hash function result from the second computing device and using the hash function result sent by the second computing source to determine whether the digital content has been transferred from the first computing device to the second computing device.
 24. The apparatus of claim 11 wherein the controller computing device is a digital rights management controller.
 25. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising sending information pertaining to the transfer of the digital content from the first computing device to the second computing device to a website associated with the controller computing device.
 26. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising sending information to an accounting web server configured to track payment associated with the transfer of the digital content.
 27. The apparatus of claim 11 wherein the computer readable medium stores further instructions that in response to execution by the controller computing device cause the controller computing device to perform operations comprising authorizing a service control device to increment or decrement an account in response to the transfer of the digital content. 